#### 12th Standard Maths English Medium Free Online Test One Mark Questions with Answer Key 2020 - Part Two

12th Standard

Reg.No. :
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Maths

Time : 00:10:00 Hrs
Total Marks : 10

10 x 1 = 10
1. If A = $\left[ \begin{matrix} 1 & \tan { \frac { \theta }{ 2 } } \\ -\tan { \frac { \theta }{ 2 } } & 1 \end{matrix} \right]$ and AB = I , then B =

(a)

$\left( \cos ^{ 2 }{ \frac { \theta }{ 2 } } \right) A$

(b)

$\left( \cos ^{ 2 }{ \frac { \theta }{ 2 } } \right) { A }^{ T }$

(c)

$\left( \cos ^{ 2 }{ \theta } \right) I$

(d)

(Sin2$\frac { \theta }{ 2 }$)A

2. If $\rho$(A) = r then which of the following is correct?

(a)

all the minors of order n which do not vanish

(b)

'A' has at least one minor "of order r which does not vanish and all higher order minors vanish

(c)

'A' has at least one (r + 1) order minor which vanish

(d)

all (r + 1) and higher order minors should not vanish

3. In the system of liner equations with 3 unknowns If $\rho$(A) = $\rho$([A|B]) =1, the system has ________

(a)

unique solution

(b)

inconsistent

(c)

consistent with 2 parameter -family of solution

(d)

consistent with one parameter family of solution.

4. The area of the triangle formed by the complex numbers z,iz, and z+iz in the Argand’s diagram is

(a)

$\cfrac { 1 }{ 2 } \left| z \right| ^{ 2 }$

(b)

|z|2

(c)

$\cfrac { 3 }{ 2 } \left| z \right| ^{ 2 }$

(d)

2|z|2

5. If z = a + ib lies in quadrant then $\frac { \bar { z } }{ z }$ also lies in the III quadrant if

(a)

a > b > 0

(b)

a < b < 0

(c)

b < a < 0

(d)

b > a > 0

6. If ax2 + bx + c = 0, a, b, c E R has no real zeros, and if a + b + c < 0, then __________

(a)

c>0

(b)

c<0

(c)

c=0

(d)

c≥0

7. The value of ${ cos }^{ -1 }\left( \cfrac { cos5\pi }{ 3 } \right) +sin^{ -1 }\left( \cfrac { sin5\pi }{ 3 } \right)$ is

(a)

$\cfrac { \pi }{ 2 }$

(b)

$\cfrac { 5\pi }{ 3 }$

(c)

$\cfrac { 10\pi }{ 3 }$

(d)

0

8. The pricipal value of ${ sin }^{ -1 }\left( \cfrac { -1 }{ 2 } \right)$ is _________

(a)

$\cfrac { \pi }{ 6 }$

(b)

$\cfrac { -\pi }{ 6 }$

(c)

$\cfrac { \pi }{ 3 }$

(d)

$\cfrac { -\pi }{ 3 }$

9. Angle between y2 = x and.x2= y at the origin is

(a)

${ tan }^{ -1 }\cfrac { 3 }{ 4 }$

(b)

${ tan }^{ -1 }\left( \cfrac { 4 }{ 3 } \right)$

(c)

$\cfrac { \pi }{ 2 }$

(d)

$\cfrac { \pi }{ 4 }$

10. Consider a game where the player tosses a six-sided fair die. If the face that comes up is 6, the player wins Rs. 36, otherwise he loses Rs. k2 , where k is the face that comes up k = {1, 2, 3, 4, 5}.
The expected amount to win at this game in Rs. is

(a)

$\cfrac { 19 }{ 6 }$

(b)

$-\cfrac { 19 }{ 6 }$

(c)

$\cfrac { 3 }{ 2 }$

(d)

$-\cfrac { 3 }{ 2 }$